1. Field of the Invention
The present application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2009-248216, filed on Oct. 28, 2010, entitled “PORTABLE ELECTRONIC DEVICE”. The content of which is incorporated by reference herein in its entirety.
2. Description of the Related Art
Hitherto, as an apparatus for projecting an image onto a wall surface or a screen, there is a so-called projector. A mainstream projector is an apparatus of a so-called standing type to which power is supplied from a commercial power source and which is used in a state where it is fixed in a predetermined position. The projector of the standing type, in a fixed state, projects an image onto a wall surface or a screen in a fixed place.
On the other hand, in recent years, a portable projector which is small and easy to carry is proposed as the projector. For example, Japanese Patent Application Publication Laid-open No. 2007-96542 (patent document 1) discloses a portable terminal with a projector function, having an upper cabinet, a lower cabinet, and a hinge connecting the upper and lower cabinets so as to be swingable, and in which a projector having a lens and a light source is mounted.
The conventional projector of the standing type uses a light source of high luminance for projecting an image onto a large screen and, since an amount of heat generation from the light source is also large, is provided with a fan and a vent for improving heat dissipation efficiency. However, since a portable terminal with a projector function in recent years is constructed compactly, if a mechanism for dissipating heat generated by a light source of a projector is added, it is considered that the portable terminal becomes large.
In the conventional portable terminal with the projector function, in the case of continuously using the projector, temperature rise near the light source has to be considered. In particular, in the case of a portable electronic device such as a cellular phone, since the skin of the user directly touches the surface of the terminal at the time of speech communication or operation, the user easily feels the temperature difference that the projector mounting position is warmer than the other part. There is consequently the possibility that the user of the cellular phone feels unpleasant.
For example, in the patent document 1, as an example of the portable terminal with the projector function, examples of a folding type, a slider type, and a straight (candy bar) type are illustrated. In portable terminals of all of the types, a light emitting unit of a projector is provided at the front end near the receiver, but a mechanism for cooling it is not provided. Consequently, after use of the projector, the portion around the receiver becomes warm. When the user makes a telephone call by using the portable terminal, the user feels warm by his/her ear and may feel unpleasant during use.
Considering a situation that the user carries the portable terminal of the patent document 1 after use of the projector, the portable terminals of all of the types have a structure that heat generated by the projector warms the surface of the portable terminal in a portable mode. Consequently, a temperature difference occurs between a part heated (for example, a part around the receiver) and the other part. Due to this, there is the possibility that the user feels unpleasant when he/she carries the portable terminal by hand or touches the portable terminal in order to make a telephone call with the portable terminal.